In this study, using the inner petals of Chimonanthus praecox (L.) Link ‘Meirenzui’ in five flowering stages (budding, germination, initial flowering, full blooming and final flowering) as materials, we investigated the change of the chromaticity value, the contents of anthocyanidin, soluble proteins, soluble sugar and the activities of superoxide dismutase (SOD), phenylalanine lyase (PAL) during flowering, and analyzed the correlation between the indicators, so as to reveal the characteristics of physiological and biochemical indexes during the floral color change of C. praecox (L.) Link. The results showed that: (1) from budding stage to final flowering stage, the hue a^* of ‘Meirenzui’ petals decreased sharply, while the value of brightness L^*, hue b^*, chroma C^* and hue angle h° increased gradually. (2) During the flowering process of ‘Meirenzui’, the contents of flavonoids, anthocyanins and chlorophyll in petals gradually decreased, while the contents of carotenoids increased first and then decreased. (3) The soluble protein content of ‘Meirenzui’ petals decreased significantly in the germination stage and full blooming stage, while the soluble sugar content decreased to the lowest value in the initial flowering stage. (4) The PAL activity of ‘Meirenzui’ petals decreased first and then increased with the flowering process, while the SOD activity increased significantly first and then remained stable. (5) There was a significant correlation between the chromaticity value of ‘Meirenzui’ petals and the contents of flavonoids, chlorophyll, anthocyanin, soluble protein and PAL activity. The results showed that C. praecox (L.) Link ‘Meirenzui’ floral color change is the result of the joint action of anthocyanins, flavonoids and chlorophyll, but the change of anthocyanin content plays the most direct role, soluble protein, SOD and PAL play an indirect role in the change of floral color through physiological metabolic pathways.